Oil distillation



March 9,1926. 1,576,401

J. E. BELL OIL DISTILLATTON Filed Oct. 7, 1921 '7 Sheets-Sheet l I wdew" March 9 1926.

' J. E. BELL on DISTILLATION 7 Sheets-Sheet 2 1,576,401. I J. E. BELL OIL' DISTILLATION Filed Oct. '7, 192

'7 Shee,ts-Sheet 4 Peteiu'tecl llller. 9, Tit-3Z6.

JQLEEN E. BELL, 0F BROOKLYN, NEW YORYL, ASEBIGNOR 31% SINULAT'Z PANY, 0F CHICAGQ, XIJL NOISfA GORZOELATION 0H Michell.

41 n we w a I 23ml! (4 d I "let OIL DISTILLATIQN.

Application filed October '1 '0 all whom it may concern:

Be it known that I, JOHN BEllL, a citizen of the United States, residing at Brooklyn, count-y of Queens, State of New York, have invented certain new and useful Improvements in Oil Distillation, of which the following is a specification.

My invention relates more particularly to the distillation of crude petroleum and has for its ohject in one operation to effect the division of the numerous hydrocarbons of clifierent specified gravities and boiling points contained in the oil into the desired number of cuts. In the process of fractionel distillation as ordinarily practiced the oil is slowly heated through th'erange of temperatures in which the desired distillotes are given off, the vapors being condensed as they are given oil. Cuts are made at successively higher temperatures, the particular points at which the cuts are made being determined by the gravit-ies of the components which are, to be embraced in the respective fractions 01' cuts, as they are more commonly called.

'It is the object, for obvious reasons, to make theaiivision between the cuts as sharp as possible, that is to say, to ovoid the presence in any cut of hydrocarbons other than those of the desired gravities. In practice, however, this has been only approxi instely attained, some compounds of heavier gravities being carried over with those of lhglrtcr grovities and some of the lighter oils remaining after the temperature has been raised shove their.boilingpoihtflsl it is the purpose of my invention tolimlp-rov the resultsol the distillation operation "in, respect to the sharpness of the we and economy can-(l efficiency of OPeretioofWVith this in View I provides number of stills, which preferably lest-least equal to the number of cuts to he made, flowing the oil through the stills seriotiimjz 'nd maintainthe stills in the. series at temperatures which rise successively from-thefirst stilhwhich re.

ceives the crucle petroleum to the last, still rrom "which the reslclueis d own oil". The

oil is preferably lowed continuo islv'from thefirst to the lest 'etill, receiving (lolitioncl. heet in. each successive still by orm hcoinponcnts of successively higher lioiiingpoiots are veporizecl and. driven oli. The vapors from'each still (except the first.) are caused '7 to "yield up eportion of their heot'to the oil 7, 1921. Serial No. $436,038.

formealtherein, and pass to the condehser in the next still of yet lower temperature. It is known that, other things heingr equal. the nearer the temperature of the condomsing surface or medium is to the temperature of the vapor being condensed, the heavier the condensate and the hotter the sepe 'otion or out eliectell between the hyrlrocz hens condensed and the hydrocarbons which as cape as vapors. "3y lez-irlii g the vapors from. a stillo't the series into, the still of next lower temperature encl. condensing, their therein, this conditiozul'svorehle to iiccnrste cutting, is realizeci; l urthermcre, the heat necessary forcontlucting the (lie ilntion. is economizecl in this mariner as the moors. condepsiog in the condensing coils hfthe several stills give up their heat oi veporiiw tion as Well as the to which the temper store difference is time to the oil th employ an. eclllitioi'iul condensing :m iis be tween successive stills in u'llichh es the hem-'iei' vapors are to some stile clnnlex'isml, preferehly hv being sprayed xvi 51 coosome "fool the conzlerlser col more oithe of lower t mperature iiiolensete the}; be when olii 'sepere l the respective still condensers and inte medilhle' condensers hut ordinarily, and in the specific embodiment of my invention shown anti. hereihizil'ter described, I: prefer to take oli' the'contlensale at, the intermediate conle'nsers only. in the preferred einliloclin'ient of the invention 1 further economize host why passing the oil between stills through heat exchangers through which coiulensiitc from condom rs of higher teinperz inre floo s, thus not only raisingtemhero "of the oil before it ehl rst-he still oi h temperature but lowering the tempers.

of the condensate.{lthcrohjects "vantages of my lire" t from the drawings on l the 'i'oli'otving: tie scriptioh in which I have setforth the pre ferred term of my inveotion; It

in one or email 101': will he ogitherecl" understood, however. that the specific disclosures are for the purpose of exemplification only and that the scope of the invention is defined in the following claims in which I have endeavored to distinguish it from the prior art so far as known tome,

embodying my invention in a preferred form, in front elevation; Figs. 2 and 2 together constitute a plan view of the same,

parts being broken away to show the interior construction; Fig. 8 a vertical section of an element'thereof; Fig. 4 is a vertical longitudinal section of one of the stills of the plant, parts being shown in elevation; Figs. 5 and 5 show a section on the line 5-5 of Figs. 2 and 2. Fig. 6 shows a vertical section of a detail, and Figs. 7 and 8 diagrammatically show pairs of adjacent stills with associated apparatus and schematically illustrate the operation of the apparatus. In the specific form of the invention chosen for illustration the plant comprises ten stills, though the number thereof in practice will depend upon the number of cuts which it is desired to make. The oil to be treated after being pre-heated in an apparatus to be presently described, is fed to the. first still 10, which is maintained' at the lowest temperature of the series and thence is fed successively to stills 10", 10, 10 and others, its temperature being raised step by step until-it reaches the final still 10 of the series from which the tarry residue is removed in liquid form. Fractional distillation is accomplished in this manner, the distillates or cuts from the sncces ivestills being successively of higher by r iling points.

Before entering the first still 10 of the series the oil to be treated is first pre-heated by means of the hot tarry residue from the last still of the series in a group of heat exchangers 11, 11", 11, seen at the right of Fig. 1, which are similar in construction, and one of which is shown in section on an enlarged scale in Fig. Looking first at the lastmamed figure it will be seen that each of these heat interchangers comprises a cylindrical shell 12 w itlrends 13, 14 which are closed except for the inlet opening 15 in the bottom end and the outlet opening 16 in the upper end. The interior of the merehanger is divided into a lower. oil cha nher 17. an upper oil chamber 18 and an 1n- ;termediate hot tar chamber 19 by horizontal heads-:20, 21. The heads are connected by tubes 22 through which the oil introduced through the bottom opening passes through the hot tar chamber into the upper oil chamm1". From the latter the oil escapes through the 'oulet opening 23.

The tubes 22, to

is connected by pipe 24 to the inlet openin of the next heat interchanger in order, ant the oil outlet opening of this second heat lnterchanger 11 is connected by pipe 25 to the oil inlet opening of the-third heat intern-hanger 11. The oil outlet openingof the last said heat interchanger is connected by pipe 26 to the inlet of the first still 10. The vapor outlets 16 of the respective heat interchangers are connected by pipes 27 to the vapor line 28 from the first of the stills.

The hot tar chamber in each of the heat interchangers is provided with an upper in let opening 29 and a lower outletopening 30 and with bailies 31. The hot tar entering at the top of the tar chamber flows downwardly about the oil tubes therein and in a. direc? tion the opposite of that of the oil, and imparts its-heat to the latter. The tar inlet opening of the last of the elements 11 is connected by pipe 32 to the last and hottest of the. stills, and receives its supply of hot tar therefrom. From heat interchanger 11 the hot tar flows through pipe 33 to the tar chamber of the second heat interchanger, and from the latter by pipe 34 to the tar chamber of the first heat inter-changer 11* from; which it may be led away to any suitable .s'torage receptacle in relatively cool condition.

Thestills may all be of identical construction, except in so far as modification may be necessary because of the end positions of the first and last stills, iespcctivel y. 1n the preferred form of the invention shown in the drawings, however, I lmveiprovided means for introducing steam int 0, four hottest. stills shown at the left of 1 2 and this makes it desirable to introduce certain ditl'erences in construction which will be hereafter specifically described. All of the stills are alike, however, in that each comprises a horizontal drum of usual form, having the usual va )or dome 36. Each still ma also be heate in any wellknown or re erred manner and it has therefore not een tlioiwlit advisable to complicate the drawings by showing the heating means. i

It will be convenient to first follow the flow of oil through the series of stills and then to describe the course of the vapors. Reference has already been made to the fact that the oil is introduced at the rear end front end thereof and on the side opposite fron1'the inlet at 37. From the outlet 37 it" is led downwardly by pipe 38 to a manifo'ld, 39 by which, it is distributed through a number of heat inter-changers 40" through which condensate from the stills of.higher temperature is led, as-will be later described, thus heating the oil. From the heat inter: changers 40 the oil is collected by a manifold 41 and conveyed by pipes 42 to the rear end of still 10". The connections between stills 10, 10", 10, 10' are simi lar to those described between stills 10 and 10", so that between the stills of each pair except the last-two the oil is raised in temperature by heat absorbed from the condensates from the stills of higher temperature. From the still 10 oil is led to the last still l0 directly by the pipe 43. As each of the stills is maintained at a omcwhat higher temperature than the imilied-iatcly preceding still the temperature of the oil is raised step by step, and the componbnts thereof, except the heaviest, are driveuoli in vapor form in groups of successively higher boiling points, known in theart cuts. 1 f

I shall now describe the disposition that is made Of the distillates drivenoff from the respective stills beginning with that of the highest temperature shown at the left end otthe'scries in Figs. 1 and 2 but first it is to be observed, as previously mentioned, that the tour stills of highest temperature are supplied with steam through a main 4%, branches 45 leading the steam from said main to stills 10 10", 10, 10, which are provided each with a series of longitudinally extending pipes 46, connected to the respective branches and perforated or slot-ted to directthe steam into the heavy oil at the bottom ot the still. By the introduction of the steam thefoil agitated and circulated in the respective stills and the formation of carbon and coke reduced, and, what is of more importance, the temperatures of vaporization are lowered; I

The vapor domes of the respective stills are connected by pipes 47 to avapor line 18 at the front of the series of stills. The

lnanch lines 47 are provided with valves receives the vapors from each of thestills and conducts them to a condenser 53, the un condenced vapors from the latter cscal'iing by pipe olto'a condenser in the still. ot' next lower temperature,-

The condensers 53 are alike throughout the plant and the description of one will serve for all. The construction is shown in vertical section in Fig. 6. It comprises a shallow rectangular casing 56 divided by a horizontal header 57 in which is mounted a large number of tubes 58 which extend upwardly from the header and are closed a their upper ends by the 'top wall 59 of the casing. Each of these tubes opens into the condensate space 60 below said header and .is perforated at 61 near the top thereof.

Above the header is the vapor space or chamberf62 into which such tubes project and this chambcr communicates with the dovvncomer vapor line 52 through avapor inlet 63 formed in the end member 64 of said cascade condenser. A vapor outlet 65 is formed in end member 68 of the cascade condenser and communicates with pipe 54-, above mentioned, which leads tlre'vapors from the cascade condenser to the still condenser 55 in the still of next lower temperature. with a rcllux inlet chamber (37 which receives reflux condensate from an inlet pipe (i8, u port 69 permitting the condensate to'llow into the chamber 60 oi the cascade condenser. The end member (i'l formed with a condensate out-let chamber 70 which (comn iunicates at 71 with the vapor chamber near the bottom thereof and also with'condensate outlet tubes 72 and 73. 1

The operation of the cascade condenser will appear from the above description. The vapors entering the inlet 63 flow through the vapor chamber in a circuitous course about the tubes therein and the reflux condensate entering the chamber 60 is sprayed through the pipes 58 into the vapors in the vapor chamber, partially cooling the vapors and condensing the heavier componcnts thereofalitllicilig heated to some extent thereby. The condensate collccts'in the bottom er the vapor chamber and flows therefrom to the coiul'cnsutc outlet. chamber 70 and thence through the.- outlet pipes T7: and 73. The reflux l'rointhc last cascade condenser of the series, to wit, that shown at the left in Fig. 1,'is led by pipes 73 and 74 to the heat inter-changer 40" of a series of heat interchangers towh'ich reference has heretofore been made, serving; to heat the oil in its passage from still to still. From heat interchunger -10! the oil passes by pipe 7 to heat inter-changer 40, and soon through eachof the heat interchangers of the series and is finally drawn off in i'clath cly cool condition through pipe 76.

As heretofore stated, the e'pors which are not condensed in the cascade condenser just described flow through the pipeot to a still condenser 55 in the still of next highest ten'iperaturc. The constructionot' this still condenseris shown.,ln idottedz lines in The end member 66 is also formed in the still of next lower temperature and comprise a longitudinal pipe 77 located near the bottom of the still into which pipe 54 leads. A large number ofbumch-pipes'ita are connected to the'inain pipe 77 and are so disti'ibuted thereon as to extend to every part of the still, the body of the pipes being Y substantially submerged in the oil, but the ends thereof, which are open, extend into the vapor space in the still. The vapors entering this still condenser from the still of higher temperature are largely condensed therein, the branch pipes forming a condenser of large superficial area maintained at the temperature ot-the oil inthis still which is somewhat lower than the temperature of the vapors as they enter the condenser. By reason of the relatively small temperature ditlercntial between the vapors and the condenser and the extensive \vorking, surface of the latter. the vapors are condensed under mostlavora'hlc conditions for making; a sharp cut as previously stated. small proportiou ot' the vapors'arc uncondensed and escape through the ends of the condenser tubes into the vapor space-til the still in which the condenser is located and mingle with the vapors generated in the still which are of nearly similar character. 7

Thus in the case oteach ot the stills into which steam is introduced, which for the sake of brevity I shall call the steam stills.

the vapors after undergoing apreliminary cooling and bart-tal condensation in :1 cascade condenser, are condensed in a condenser the uncondcnscd vapors from such condenser incorporated with thevapors generated in such still and passed along the series.

The cuts or fractional products areprc'l'erably taken oil at the r sptartivc cascade condensers, the ninth cut. to wit. that. of highest average gravitv hciiig taken olt 'troin'thc last cascade condenser 5:2 the eighth cut, which is next in order of gravity. being; taken oil from the next cascade condenser 523", and so on. The condensate discharged into each cascade condenser is mainly drawn from the still condenser into which the vapors from such caseadecoiuleuser are led, thus the'c'ondensate discharged into the last condenser 53 by pipes 79, 68, and the condensate from the still condenser in each of the other stills, (except the last, which contains no condenser) is discharged into the cascade condenser, from which it receives vapors through similar pipes 79 and 68. The supply of condensate may be more or less supplemented by condensate received. from the adjacent cascade condenser of lower temperature through pipe 80.

As best seen in Figs. 2 and 2, for each terial,provided they afl'ord contiguous passages for the oil and condensate, respective ly, whereby the absorption of heat by the one from the other is facilitated.

IVere steam introduced into all of the stills of the series, or were no steam introduced into any of them, the construction heretofore described, including the still condensers, might be carried throughout the series toadvantag'e. But while there is a material advantage in introducing steam into the hotter stills to ettect the agitation of the heavy oil therein, diminish coke deposition and by its partial pressure reduce the boilingpoint, it is undesirable in the stills of lower temperature and in which the oil is ot lighter average composition because by its partial pressure it disturbs the cod points of the cuts. It is for this reason that steam is only introduced into the stills of highest temperature and as the vapors therefrom contain steam it is undesirable to introduce them into the vapor spaces of the nonsteam stills. In the nonstcam stills. therefore, I provide separate condensers tor the vapors coming from the steam stills and from the non-steam stills of higher temperatures, respectively, the condensers tor the vapors containing steam be ing closed while the condensers tor the vapors which do not contain steam open into the vapor spaces of the respective stills. In Fig. 2 l have shown in plan and in Fig. t, in vertical section, a still containing the separate condensers. In Fig. 2 the still 10 is shown as so provided, it beingunderstood -that all the stills shown to the right thereof are similarly equipped. The larger condensers occupying the trout portions of the still are of the open variety, similar in all respects except lcngth to the open still con dcnsers previously described. The closed condensers, located at the rear ends of the respective stills comprise upper and lower headers 86, 87 connected by small bent vapor tubes 88, see Fig. 5. The vapor introduced into the lower header from the still of higher temperature rises in the multiple small tubes and is largely condensed therein, the uucondcnsed vapors flowing into the upper header and thence out of the still and through header 95 and pipe 97 to the still of next lower temperature. IVhile I have shown the last of the non-steam Stills 10 as containing an open condenser this is not used where steam is used in the steam stills, for the reason above stated, but only romeo: l i

is uses i. ii lion steam is on is the venor from st ll a n Ml mos c; our nc o LZ-oncl pine to "the open corn ll 1 is carried by pipes 89, $0, 9i in ecier 9 said; lino in; 1 lie 9 in pipe 52 isclosec curl 92? in ills vapor nieniiiolcl. e8

curl downcoincr pipe 8%.?" rcspccti ely,' ere open The non-steam stills ore provided at ilic rear ends with a vapor iieruler cnms ug the upper moni'li'ilcls of theclosecl still condensers end provided between the skills oi the respective pairs, 'Wil li valves n'i in prevent direct flow rliereilirougli.

'l'bowm onlci pipes 97 provielecl with valves 98 lcoiltlic uncondcnsecl moors from the flop manifold of encircle condenser to the bottom manifold of the i llowing closed.

cijnillenscr so that the vapors coming from no s'lzeem. siills are subjected to successively "nearly similar character as possible and therefore the condensate from each closed condenser, insleocl of being; combined with i condensate from the open condenser in some still is stlclecl to the reflux from own condenser of n hotter slill, i. e., a v to bi l? loll; tliereoii-os shown in Figs. 1 (illil 1": in the psrcicular" arrangement ill retro: the condensate from each closed "eraser :uizleal to file condensate from coon condenser of the ucljoining'liotter f. this "purpose. pipe 99 is con- C the lower licncler of. each closed i r ,encls ioibe front of the *ries of stills-coil then tothe r ercnce io 1. and i, being co into the reflux pipe 79 or the next siiil.

, and i reference characters have been lice. anal legends have been-applied io slice? in o diagrammatic woyilic operalion of the still in ie clisiillotion giant. Fig. 7 schematiczg shows the operation of adjacent stills where in been o them, or in neither of cmion urljcceut stills Where vapors conung slim-on are enriplnyecl to heat the oil in ills soils owl are thereby condensed but woere one unconilcuscd steonrcontnming temperatures in the closed condensersmul ussocialccl apparatus 1, direct sieoni is usccl, such as stills vapors are not allowed to mingle with the still. vapors, such as stills l0 and 10.

"This 'to be nolecl time the vapors pass through the cascade boxes or condensers sue cessively from left to right, "from hotter lo cooler and the condensate or reflux from right to left, i. c., from cooler to hotter. The vapors are therefore submitted to 'i'rugtionel condensation by beingsproyed with liquid which is suificiently cooler than. the vapors .lo client the clesireii, condensation of the lighter components of the vapors bulzfwliosc temperature is. solliciently high to secure sharpness of out. Likewise the condensate is subjcclecl'to fractional distillation in con,

lociu'illi successively holler bodies of vapor which take up the lighter ends. By the combined fractional conclensation and dis tille'tion thus effected the cuts or condensates from iberespeclzivc rellux or cascade boxes are'clearerl up, the apparatus thusjocting as a series or re-run stills.

The cuts or condensates from the respective reflux boxes or condensers are or may "be maintained separate throughout the op porcine and may be separately storerl or mixed in any desired proportions to form commercial precincts. In ordinary practice condcnsale is taken of? only from those one code boxes or condensers in which the con cicnc-y in heat absorption is realized.

ll claim: I 1, A. process of fractional distillation and condensation of oil which comprises flowing the oil to l e treated through a series ofstills maintained at successively higher voporizing; lemperutures, condensing part of the heat therefrom by the oil in a still. of lower temperature and heating the oil intermediate successive stills by the condensed vapors from stills later in the series.

2. A process of fractional 'distillation anol condensation of oil which comprises flowing the oil to be treated through e series oi stills maintained at successively higher vnporizin}; temperatures, condensing part of the vapors given off in each still by absorbing heal; therefrom by the oil in the next still of vapors given oil in each still by absorbing lower temperature, and heating the oil intcrinecliate successiye stills by the condensed vapors lll'Oln stills ioterln the series,

3. A process of fractional distillation and condensation of oil which comprises flowing the oil to be treated through a series oi. Stills maintained at successively higher vaporiyr ing temperatures. condensing part. of the vapors given off in each still i absorbing heat therefrom, first by the condensate of pors these vapors formed in a still of lower temperature. and thenby the oil' in the said still of lower temperature, and heating the oil intermediate successive stills by the condensed vapors from stills later in the series t. A process of fractional.distillation and condensation of oil which comprises flowing the oil to he treated through a series of stills maintained at successively higher vaporizing temperatures, condensing part of the vapors given oft in each still and absorbing heat therefrom, first by the condensate of these vapors tormed'in a still of lower temperature mingled with condensate of vapors from the latter still and then 'by the oil in said still of lower temperature, and heating the oil intermediate successive stills by the condensed vapors from the stills later in the series. v

5. A process of fractional distillation and condensation of oil which comprises flowing the oil to be treated through a series of stills maintained at successively higher vaporizing temperatures, condensing part of the vapors given off in each still by absorbing heat therefrom bythe oil in a still of lower temperature and isolating the condensate so formed, from the oil in the still of lower temperature, and heating the oil intermediate successive stills by the condensed vapors from stills later in the series.

6. A process of fractional distillation and condensation of oil which comprises flowing the oil to be treated through a series of stills maintained at successively higher vaporizing temperatures, condensing part of the va uors- 45 g iven oft" in each still by absorbing ieat therefrom, first by the condensate of these vapors formed, in a still of lowertemperature, and then by the oil in sald still of lower temperature, isolating the condensate so formed, from the oil in the still of lower temperature, and heating the oil intermediate successive stills by the condensed vafrom the stil's later in the series.

7. A process of fractional distillation and condensation .of oil which comprises flowing the oil to be treated through a 'seriesof stills heated to successively higher, vaporizing temperatures and condensing part of the vapors given oil in each still by absorbing heat therefrom, first by condensate of these vapors formed in a still of lower temperature and then by the liquid oil in said still of lower temperature.

8. A process of condensation of oil which comprises flowing the oil to betreated through a series of stills fractional distillation and heated to successively higher vaporizing temperatures, condensing part of the vapors given off in each still by absorbing heat therefrom, first bv the condensate of these vapors formed in a still of lower temperature, and then by the liquid oil in said still of lower temperature, and isolating the condensate so formed.

9. A process of fractional distillation and condensation of oil which comprises flowing the oil to be treated through a series of stills maintained at successively higher vaporizing temperatures and condensing part of the vapors given oil in each still by absorbing heat therefrom, first by the condensate of these vapors formed in a still of lower temperature, mingled with the condensate of the vapors given off in said still of lower temperature and then by the liquid oil in said still of lower temperature.

10. A process of fractional distillation and condensation of oil which comprises flowing the oil to be treated through a series of stills heated to successively higher vaporizing temperatures, condensing part of the vapors given .oflf in each still by absorbing heat therefrom by the oil in a still of lower tem-' perature, isolating the condensate so formed, from the'oil in the still last mentioned and permitting the uncondensed vapors to escape with the vapors from the oil of that still, a

absorbing heat therefrom by the oil in the stills of successively lower temperatures, and heating the oil intern'iediate successive stills by the condensed vapors from stills later in the series.

12. A process of fractional distillation and condensation of oil which comprises flowing the oil to be treated through a series of stills heated to successively higher vaporizing temperatures, and fractionally condensing the vapors fromeaeh still, except the first, by absorbing .heat therefrom, first by the condensate formed by condensation of these vapors in each of the stills of successively lower temperature and then by the oil in the said stills of successively lower, temperatures, and heating the oil intermediate successive stills by the condensed-vapors from stills later in the series.

13. A process of fractional distillation and condensation of oil; which. comprises flowing the oil to be treated through a series of stills heated to successively higher vaporizing temperatures,fiYac-tionally condensing the vapors from each still, except the first,

14. A process of. fractional distillation and condensation of oil which comprises flowing the oil to be treated through a series of stills heated to successively higher vaporizing. ten'iperatures and fractionallycondensing the vapors from each still, except the first, by absorbing heat therefrom, first by the condensate of these vapors formed in each of the stills of successively lower temperature mingled with the coi'idensate of vapors from the st-ill in which such first mentioned condensate is formed, and then by the oil in the said stills of successively lower temperature, and heating the oil intermedi ate successive stills by the condensed vapors from the stills later in the series. I

15.. A process of fractional distillation and condensation of oil which comprises flowing the oil to-be treated through a series of stills, heated to successively higher vaporizing temperatures, condensing part of the vapors from each still, except the first, by absorbing heat therefrom by condensates of vapors from Stills of lower temperatures, and heating the oil intermediate successive stills by the condensed vapors from stills later in the series.

.16. A process of fractional distillation and condensation of 'oil- Whicli'comprises flowing the oil to be treated through a series of stills heated to successively higher vaporizing temperatures, condensing part of the vapors from each still, exceptthe first, by absorbing, heat therefrom by direct contact ,with condensates of vapors from stills of lowertemperatures, and heating the oil intermediate successive stills by the condensed [vapors from stills later in the series.

17. A process of fractional distillation and condensation of oil which comprises flowing the oil to be tr ated through a series of stills'heated to successively higher vaporizing temperatures and condensing part of the vapors from each still, except the first, by spraying, them with condensates 0t va pors from stills of lower temperature, iniugled with condensates of the vapors first mentioned produced in said stills of lower and condensation of oil which compr such treatment absorbingheat therefrom by the oil in the stil-ls'ofloiver temperatures/.45: 19. A process of fractal-rial distillation; and condensation of oil which coi'nprises flowing; the oil to be treated throu lr a series of stills heated to successively hig ier vapor izing temperatures, condensing part of the vapors from each stillyexcept the first, by

spraying them with condensates of vapois from stills of'lower temperatures mingled with condensates of the vaporsfrom the stills of higher temperatures produced by absorbingheat therefrom by the oil-in stills of lower temperatures, 'tlien mingling the vapors uncondeused in such treatment with ten'iperaturcs, and heating the oil iiitermedi ate successive stills by the condensed vapors from stills later in the'serles.

'20. A process of fractional distillation so the vapors given off in such stills of lower and condensation of oil which comprises flouting: the oil .to be treated through a. series of stillsheated to successively higher vaporizing temperatures, COnClGIiSilig part of the vapors given oil" in each still absorbing- .li'eat theretrom,- first by the condensateof such vapors produced by such heat'al'isorption and then by the liquid oil in a still of lower temperature, and heating the oil in' its passage from still to still by causing it to absorb heat from the condensates ot' vapors {P0111 all the stills of higher loinperatui'e. v I

QLA process of .iIltIClZlOlltll distillation flowing the oil to be treated through a C J of stills lieated to successively higher va poriizing temperatures," condensing part of the vapors given oil in each still by absorbing'heat therefrom by the oil in a still of lower temperature, preheating the oil priorto its entry into the first still by residuuni from the last still and heating the oil between adjacent stills by iiiipart-ing heat tl'iereto by the condensates of apers given off in stills later in the series.

22. A. process'of fractional distillation and condensation of oil which con'iprises flowingthe oil to he treated through a series of stills heated to' successively higher vaporizingr tei'i'iperatures, condensing part-totthc vapors given off in each still by absorbingheat therefrom, lirst by the condensate of these vapors formed by such heat llliSUl'PtlOll and then by the liquid oil in av still of lower temperature and preheating the 'oil pridr to its entry into the? first still by the residiiuni from the last-still.

221A process of fractional distillation and condensation of oil which comprises flowing the'oil to be treated through a series o'tstills heated to successivelylnglier vaporizingtemperatures. condensing part of the vapors given otl in each still by absorbing heat therefrom by the oil in a still of lower temperature, heating the oil between adjacent stills by imparting heat thereto from condensates from all of the stills of higher temperatures, and preheating' the oil prior to its entry into the first still by the residuum from the last still;

A process of fractional distillation and condensation of oil which comprises flowing the oil to he treated through a series of stills heated to successively higher vaporizing temperatures, introducing steam into the oil in a plurality of stills at the end of the series, condensing part of the vapors given off in each still bv absorbing heat therefrom by the oil in a still lower temperature while isolating the vapors from the steam stills from the vapors of the. stills into which steam is not introduced and mixing the condensate ot' the vapors given off in each steam still with the condensate formed in the still of next higher temperature.

In apparatus of the class described. a. series of stills, means for maintaining the stills at successively higher vaporizing temperatures, means for feeding crude oil into the first still of the series and for conveying oil from each still to the next succeeding still of the series, means for introducing steam into the last still of the series, closed condensers in the preceding stills and connec tions between such closed condensers and the vapor space in the steam still, open cpndensers in each of said preceding stills\0pening into the vapor space thereof, connelctions from the vapor space of each preceding still, except the first, to the open condensers in the next preceding still of the series, and means for collecting together the condensate pro-- duced in each closed condenser with the condensate produced in the open condenser of the next succeeding still of the series.

2G. In' an apparatus ot'ithe class described, a. series ()fiStlllS, means for maintaining the stills of the series at succesively higher vaporizing temperatures, means for feeding crude oil into the first still oj the series and conveying oil from each of said stills t0 the next succeeding stillofv the series, a condensing coilin each still except the last, means for heating oil flowingrbetween successive stills by means of condensate from succeeding stills of theseries and means for conveying the vapor from each still to the condensing coil in a'pre'ceding still of the series. r

27. In an apparatus of the class described, a series of stills, means for maintaining the stills of the series at successively higher vaporizing temperatures, means for feeding oil tothe first still and from said first still to the second still cruise on, a condenser in each still except the last, the condenser opening into the vapors space of the still, means -for heating oil passing between successive stills by condensate of the vapors given oil in succeeding stills of the series, and means for leading vapors from the vapor space of each still, except the first, to the condenser in the next preceding still of the series.

28. In an apparatus of the class descrihed,

a series of stills, means for maintaining the thereto. the branch pipes extending ahove the normal liquid level in the still and comn.unicatin e with the vapor space therein, means for heating the oil flowing between successive stills hy the condensates of the vapors given off in succeeding stills of the series, and means for conducting the vapors from the vaporspace in each still, except the first. to the condenser in the next preceding still of the series.

29. In apparatus of the class described-a series of stills, means for maintaining the stills at successively higher vaporizing temperatures, means for supplying crude oil to thefirst still of the series and for conveying oil from said still to the next succeeding still of the series, and so on, a condenser in each still, except the last, and opening thereinto, means for conducting vapors from each still into the condenser oi the next preceding still of the series, a draw-oil pipe for drawing otl' the condensate from each still condenser and heat interchangers for heating the oil passing hetween successive stills by this condensate.

30. In an apparatus of the class described, a series of stills, means for maintaining the stills at successively higher temperatures, a condenser in each still, except the last, connections from the vapor space of each still, except the first to the condenser in the nextpreceding still of the series, and an intermediate condenser in 'each said connection, means for-supplying to the same aniixture of condensates formed in the condensers in the next two preceding stills 'of the series, and a draw-off pipe connected to each still.

31. In-an apparatus of the class described, a series of stills, means for maintaining the stills of tlie'series at successively higher temperatures, means for feeding oil into the first still of the series and for conveying oil from each of said stills to the next succeeding still of the series, means for conveying vapors from each still, except the first, and discharging them into the next preceding still of the series, and means for condensing part of the vapors so conveyed comprising means for bringing them'in heat exchanging relation with condensate thereof iormed in said next preceding still.

= 82. In an apparatus of the 'classdescribed,

a series of stills, means for maintaining the stills of the series at successively lueller vaporizing temperatures, means for fee log: crude oil into first stillcli the series and conveying oil from each of said. stills tothc next suceeding still of the series, means for conveying vapors from each still, except the first, end discharging them into the next preceding still of the series, and means arranged- .intermedi ate the successive stills for condensing part of such vapors comprising recess for introducing therein condensates formed. from such vapors in said next preceding still mingled with the condensate m3 vapcrsvgivcn off in the lest-named still.

33 In an apparatus of the class described, a series of stills means for maintaining the stills of the series at successively higher vaporizing temperatures means for feeding; crude oil into the first still. of the series and coi'iveyiiig oil from each of said stills to the next succeeding still of the series, means for introducing steam into a still near the end of the series, closed condensers in the preceding stills and connections thereto from the 301' simce of the steam still en v 1 r g n 7 condensers 111 each 01 said preceding stills opening into the vapor space thereof and connections from the vapor space of each prccedii. ill, except the li st, to the open condenser in the nest preceding still of the series.

se. In an apparatus of the class described,v a series of stills, means for iii-einteiniog the stills ct successively higher veporizing'temperatures, means for feeding crude oil into ll c first still of the series and conveying oil from each still to the next succeeding still ofthe series, means for introducing steam into a plurality of stills near the ercil of the series, closed condensers in the preceding stills and connections thereto from the vapoi spaces the succeeding stcemstills,

stills opening into the vapor space thereof, and connections from the vapor space of the stills other than thesaicl plurality to the open condensers in the next preceding still of theseries and means for collecting togather the condensate produced in each closed condenser with the condensate produced in the open condenser of the next succeeding still of the series.

35. In an a peratus of the class described, a; series ofsti ls, means for maintaining the stills of the series at successively hi her vaporizing temperatures, means for fee ing crude oil into the first still of the series and conveying oil from each of said stills to the next succeeding still of the series, a condens ing coil in each still except the last, and means for conveying the vapor from each still to the condensmg coil in a preceding still, including a cascade condenser and connections for conveying the vapor therethrough and pipes for leading condensate from the condensing coil in the next preceding still of the series to said cascade condenser.

36. In an apparatus of the class described, a series of stills, means for meintainin the stills of the series at successively hi her vaporizing temperatures, means for fee ing crude oil into the first still of the series and conveying oil from each of said stills to the next succeeding still of the 'series, a condensing coil in each still except the last, means for conveying the vapor from each still to the condensing coil m a, preceding still, and means for separately leading away the condensate from each condenser 1nc1ucling a series of heat exchangers, there loelog me exchanger for each precedin still in the series and means for leading oi passing between successive stills through the respective heat exchangers;

Jesse-BEL 

